US3970291A - Method of preventing occurrence of pulsation in a circulating liquid for evaporative cooling - Google Patents

Method of preventing occurrence of pulsation in a circulating liquid for evaporative cooling Download PDF

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Publication number
US3970291A
US3970291A US05/536,481 US53648174A US3970291A US 3970291 A US3970291 A US 3970291A US 53648174 A US53648174 A US 53648174A US 3970291 A US3970291 A US 3970291A
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United States
Prior art keywords
circulating liquid
separator
inlet
coolant
level
Prior art date
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Expired - Lifetime
Application number
US05/536,481
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English (en)
Inventor
Takeo Yamada
Kazuo Kunioka
Toyokazu Teramoto
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JFE Engineering Corp
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Nippon Kokan Ltd
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Publication date
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Publication of US3970291A publication Critical patent/US3970291A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D9/00—Cooling of furnaces or of charges therein
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B7/00—Blast furnaces
    • C21B7/10—Cooling; Devices therefor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
    • F16L55/04—Devices damping pulsations or vibrations in fluids

Definitions

  • This invention relates to a method of preventing occurrence of pulsation in a circulating liquid for evaporative cooling flowing through a cooling stave of a blast furnace.
  • the circulating flow of the circulating liquid takes place due to the liquid density difference resulting from the liquid temperature difference between the circulating liquid within the delivery pipe and the circulating liquid of an upstream or discharging side including the cooling pipes and discharge pipe. Further, in this case, while said flow of the circulating liquid is caused to occur, the surface level of the circulating liquid within the separator is always maintained at a position lower than the position of that inlet of the separator connecting to the delivery pipe, for the purpose of principally elevating the steam separation efficiency.
  • the object of the invention is to provide a method of preventing occurrence of pulsation in a circulating liquid, for use in the case where blast furnace cooling is performed by a cooling stave utilizing an evaporative cooling system.
  • the method of the invention comprises the first step of maintaining, where the circulating liquid within a discharge pipe is in a first condition in which the fraction dryness thereof is not greater than a prescribed value, the surface level of the circulating liquid within a steam separator to be at a position higher than an inlet of the separator connecting to the discharge pipe, and the second step of maintaining, where the circulating liquid within the discharge pipe is in a second condition in which the fraction dryness thereof exceeds said prescribed value, said surface level of the circulating liquid within the steam separator to be at a position lower than said inlet.
  • said inlet is situated below the surface level of the circulating liquid within the separator, circulation of the circulating liquid starts to be effected simultaneously with the heating of cooling pipes after ignition of the blast furnace, so that even where the cooling pipes are locally heated due to the local damages of fire bricks within the blast furnace, no strong pulsation occurs in the circulating liquid. As a result, cooling of the blast furnace is smoothly carried out to cause no occurrence of such apparatus damages as explained in the prior art case.
  • the apparatus remains set at said first step, the surface level of the circulating liquid within the separator is maintained to be relatively high, and a separator capacity for vapor reception is maintained to be relatively small, and further the circulating liquid fed back into the separator through the discharge pipe flows into the circulating liquid body below said surface level in a state containing vapor therein.
  • the steam separation within the separator is not carried out with high efficiency, and a stable liquid circulation is not achieved, and further difficulties are presented in gauging and controlling the surface level of the circulating liquid within the separator.
  • said second step since the surface level of the circulating liquid within the separator is lowered up to a position lower than said inlet of the separator, the steam separating ability of the separator is improved to enable a stable evaporative cooling function to be performed.
  • the surface level of the circulating liquid within the separator is maintained to be at a position raised from the lower end of said inlet by an extent equal to a value one to two times the diameter of said inlet, while it is preferred in the second step that said surface level is maintained at a position lowered from the lower end of said inlet by an extent equal to a value one to two times the diameter of said inlet.
  • the place where the fraction dryness of the circulating liquid is measured is that portion of the discharge pipe interior which is located at a position lowered from the lower end of said inlet by an extent equal to a value five to six times the diameter of said inlet of the separator.
  • An apparatus for preventing occurrence of pulsation in a circulating liquid for evaporative cooling flowing through a cooling stave of a blast furnace comprises a steam separator having an outlet for permitting said circulating liquid to be delivered therethrough to the cooling stave and an inlet for permitting said circulating liquid fed back from the cooling stave to be supplied therethrough into said separator, a discharge pipe connecting the cooling stave to said inlet, a supplementary feed pipe for supplementarily supplying said circulating liquid to said separator, first means provided for said discharge pipe, for detecting a first condition in which the fraction dryness of the circulating liquid within said discharge pipe is not greater than a prescribed value and a second condition in which said fraction dryness exceeds said prescribed value, and second means for, when said first means has detected said first condition, raising the surface level of said circulating liquid within said separator up to a position higher than the upper end of said inlet and simultaneously maintaining said surface level at the raised position, and when said first means has detected said second condition, lowering said surface level up to a position lower than
  • a fraction dryness measuring device i.e., a void meter.
  • an automatic control device which comprises a level meter for gauging the surface level of the circulating liquid within the separator, level setting apparatus for permitting said surface level to be moved up to a prescribed position, a controller for sending output signals upon receipt of signals sent from said level meter and level setting apparatus, a valve positioner operative upon receipt of said output signals, and a valve driven by said valve positioner to control the flow of the circulating liquid passing through said supplementary feed pipe.
  • FIG. 1 is a diagramatical view illustrating piping and wiring diagram for permitting flow of a circulating liquid for use in an evaporative cooling system, utilizing the method of the invention
  • FIG. 2 is a measurement data illustrating variations with time of the quantity of circulating liquid flow in the case where the circulating liquid is permitted to flow through the cooling pipes in accordance with the prior art method
  • FIG. 3 is a measurement data similar to FIG. 2, obtained in accordance with the method of the invention.
  • FIG. 1 within a cooling stave 10 of a blast furnace (not shown) are provided a large number of cooling pipes 12 vertically extending through the cooling stave 10 in a zigzag manner, the lower ends of said cooling pipes being connected to a supply header 14 and the upper ends thereof to a discharge header 16.
  • the supply header 14 is connected through a delivery pipe 18 to a steam separator 20 while the discharge header 16 is connected through a discharge pipe 22 to an inlet 24 of the separator 20.
  • a circulating cooling liquid or circulating coolant 25 Within the separator 20 is received a circulating cooling liquid or circulating coolant 25.
  • the separator 20 is provided with a supplementary feed pipe 28 having a value 26 for controlling the circulating flow of the circulating coolant supplied into the interior of the separator, an exhaust pipe 32 having a valve 30 for exhausting the circulating coolant 25 within the separator 20 into the exterior, and a vapor passageway 35 having a relief valve 34 for keeping the vapor pressure within the separator 20 at a predetermined level.
  • the separator is further provided with a pressure gauge 36 for measuring a vapor pressure within the separator 20, and a thermometer 38 for measuring the temperature of the circulating coolant within the separator.
  • a reference numeral 40 indicates a level meter for measuring the level of the coolant 25, and in FIG. 1 a differential pressure type level meter is shown as said level meter. Different levels of pressure within the separator are introduced from the upper and lower portions of the separator through passageways 40a, 40b, respectively, into said level meter, and this level meter is thereby caused to generate an electrical signal indicating the differential pressure, i.e., the depth of the coolant 25.
  • the level meter is not limited to said differential pressure type level meter, but any known level meter can be employed which includes one utilizing a float, one utilizing radioactive rays, one utilizing the reflection of supersonic wave, and so on.
  • the discharge pipe 22 is provided with a void meter 42 at a position B lowered by H3 from the lower end A of the inlet 24 of the separator 20.
  • Said void meter 42 is a first means for determining whether the coolant within the discharge pipe 22 is in the above-mentioned first condition or in the above-mentioned second condition, and any known void meter can be employed which includes one utilizing electrodes or one utilizing a system for measuring the transmissivity of ⁇ -rays.
  • FIG. 1 an electrode type void meter is shown.
  • Within the discharge pipe 22 are disposed two electrode plates 44 in a manner that said electrode plates face each other, whereby the electric resistance of the coolant between both electrode plates 44 is measured by a resistance measuring device 46.
  • a reference numeral 54 designates an indicator for indicating the electric resistance value or vapor void.
  • a peep hole (not shown) is provided at a portion B of the discharge pipe 22 in replacement of the use of said void meter 42, whereby the vapor void can be investigated through said peep hole by a viewer.
  • a level setting apparatus 48 functions to send to a controller 50 an electrical signal for controlling the level of coolant within the separator 20, i.e., a level setting signal.
  • the controller 50 drives a valve positioner 52 upon receipt of said level setting signal and the electrical signal sent from the level meter 40 to cause the valve 26 to be opened or closed thereby permitting the level of circulating coolant 25 within the separator 20 to coincide with a predetermined level setting value and to be maintained at the predetermined level.
  • the foregoing level controlling operation is performed only when the coolant level is desired to be raised by opening the valve 26 to supply the coolant into the interior of the separator 20 through the supplementary feed pipe 28. Where it is desired to lower the coolant level, no particular operation is usually required.
  • the temperature of the circulating coolant is low, and the void meter 42 indicates that the coolant is in the above-mentioned first condition.
  • the level setting apparatus 48 is so adjusted that the level of coolant within the steam separator 20 is located at a position above the inlet 24, for example, a position L1 of FIG. 1.
  • the coolant level is below the position L1, it is so controlled as to coincide with L1 by second means comprising the differential pressure type level meter 40, level setting apparatus 48, controller 50, valve positioner 52 and valve 26, namely, an automatic control device 51, and is thus maintained at L1.
  • said automatic control device 51 When the coolant level is above the position L1, said automatic control device 51 is rendered inoperative, so that the coolant level is lowered due to that release of vapor by the relief valve 34 resulting from the elevation of coolant temperature, and when the coolant level is lowered to a position equal to or lower than the position L1, the automatic control device 51 is rendered operative to permit the coolant level to be maintained at L1.
  • This condition corresponds to the condition at said first step.
  • the circulating flow of the coolant starts to occur due to the usual convection from the initial time when the blast furnace is ignited. As a result, even when thermal load is locally applied to the cooling pipes, vapor is prevented from being rapidly generated at such local portions, therefore possible accidents due to such rapid vapor generation can be avoided.
  • the level setting apparatus is so adjusted as a second step that the level of coolant within the separator 20 is brought to a position below the inlet 24, for example, a position L2 of FIG. 1.
  • the automatic control device 51 functions to maintain the valve 26 to be closed. Accordingly, the coolant level within the separator is gradually lowered owing to the release of vapor from the relief value 34.
  • the coolant level reaches a position equal to or lower than said position L2
  • the automatic control device 51 is rendered operative to maintain the coolant level to be at the position L2.
  • the coolant rich in vapor is forcefully entered into the separator 20 through the inlet 24. As a result, no pulsation occurs in the circulating coolant.
  • the blast furnace is subjected to a successful evaporative cooling.
  • the blast furnace operation can be advanced from the initial ignition to the normal operation without running into any trouble of evaporative cooling apparatus.
  • the coolant level is kept in the first step at the position L 1 , which is higher by H 1 than the horizontal surface L 3 including the lower end A of the inlet and, in the second step, at the position L 2 which is lower by H 2 than the horizontal surface L 3 .
  • each of H 1 and H 2 be set 1 to 2 times the diameter of the inlet and the vertical distance H 3 between L 3 and the void metering position B 5 to 6 times the diameter of the inlet.
  • the fraction dryness of the circulating coolant measured at a predetermined void metering position should be set at 5 to 20%, preferably about 10%, for changing the operation from the first step to the second step. The conditions thus set permit a smooth change from the first step to the second step.
  • FIG. 2 is a data showing variations with time of the quantity of coolant flow in the case where the evaporative cooling of the blast furnace is performed by the prior art method when the coolant is in the above-mentioned first condition.
  • FIG. 3 is a data similar to FIG. 1, obtained by measuring the quantity of coolant flow using the method of the invention.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Blast Furnaces (AREA)
  • Details Of Measuring And Other Instruments (AREA)
  • Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
  • Separating Particles In Gases By Inertia (AREA)
US05/536,481 1973-12-28 1974-12-26 Method of preventing occurrence of pulsation in a circulating liquid for evaporative cooling Expired - Lifetime US3970291A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP74956A JPS5231283B2 (fr) 1973-12-28 1973-12-28
JA49-956 1973-12-28

Publications (1)

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US3970291A true US3970291A (en) 1976-07-20

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US (1) US3970291A (fr)
JP (1) JPS5231283B2 (fr)
FR (1) FR2256249B1 (fr)
GB (1) GB1493955A (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105544657A (zh) * 2016-01-04 2016-05-04 上海市政工程设计研究总院（集团）有限公司 一种单向稳压塔装置的控制方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60249794A (ja) * 1983-12-16 1985-12-10 株式会社日立製作所 分岐管および原子炉の再循環配管系

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3245401A (en) * 1964-03-05 1966-04-12 Loftus Engineering Corp Water-cooled damper
US3692103A (en) * 1970-11-03 1972-09-19 Vsesoyuzny Nauchono I I Pi Och Device for evaporative cooling of metallurgical furnaces
US3693708A (en) * 1970-09-30 1972-09-26 Vni I Preektny I Ochistke Tekn Device for evaporative cooling of metallurgical furnaces
US3723632A (en) * 1971-03-17 1973-03-27 S Beizerov Water cooling system for vacuum arc furnace
US3750629A (en) * 1970-10-23 1973-08-07 Koninklijke Hoogovens En Staal Cooled furnace and a cooling system therefor
US3818870A (en) * 1972-07-10 1974-06-25 S Andoniev System for evaporative cooling of metallurgical units

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3245401A (en) * 1964-03-05 1966-04-12 Loftus Engineering Corp Water-cooled damper
US3693708A (en) * 1970-09-30 1972-09-26 Vni I Preektny I Ochistke Tekn Device for evaporative cooling of metallurgical furnaces
US3750629A (en) * 1970-10-23 1973-08-07 Koninklijke Hoogovens En Staal Cooled furnace and a cooling system therefor
US3692103A (en) * 1970-11-03 1972-09-19 Vsesoyuzny Nauchono I I Pi Och Device for evaporative cooling of metallurgical furnaces
US3723632A (en) * 1971-03-17 1973-03-27 S Beizerov Water cooling system for vacuum arc furnace
US3818870A (en) * 1972-07-10 1974-06-25 S Andoniev System for evaporative cooling of metallurgical units

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105544657A (zh) * 2016-01-04 2016-05-04 上海市政工程设计研究总院（集团）有限公司 一种单向稳压塔装置的控制方法
CN105544657B (zh) * 2016-01-04 2017-07-18 上海市政工程设计研究总院（集团）有限公司 一种单向稳压塔装置的控制方法

Also Published As

Publication number Publication date
JPS5231283B2 (fr) 1977-08-13
GB1493955A (en) 1977-12-07
DE2461599B2 (de) 1976-05-06
DE2461599A1 (de) 1975-07-03
JPS5097503A (fr) 1975-08-02
FR2256249B1 (fr) 1977-07-01
FR2256249A1 (fr) 1975-07-25

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